Inclusion Criteria:

• * BMI 30-50 kg/m2 for at least 6 months prior to ESG
• * Diagnosis of UC with plans to undergo or who have already undergone colectomy as part of a plan to pursue eventual 3-stage ileal pouch anal anastomosis (IPAA)
• * Willing to adhere to the diet and behavior modifications required for ESG
• * Able to follow the visit schedule
• * Able to provide informed consent
• * If female, be either post-menopausal, surgically sterile, or agree to practice birth control during year of study and have negative serum Human Chorionic Gonadotropin (HCG) at screening/baseline

Exclusion Criteria:

• * Prior gastric or bariatric surgery or other alteration to upper gastrointestinal anatomy which would preclude safe or technical performance of ESG
• * Current or recent (last six months) gastric or duodenal ulceration
• * Esophageal or gastric varices
• * Significant motility disorder of the esophagus or stomach
• * Large hiatal hernia measuring \>5 cm or ≤ 5 cm and associated with severe gastroesophageal reflux
• * Severe coagulopathy, hepatic insufficiency, or cirrhosis
• * Gastric mass
• * Presence of any other medical condition which precludes safe performance of elective endoscopy such as poor general health and/or history of severe hepatic, cardiac, or pulmonary disease
• * Serious or uncontrolled psychiatric illness which may compromise patient understanding of procedure or compliance with follow-up visits
• * Unwilling to participate in an established diet and behavior modification program, with routine follow-up
• * Ongoing corticosteroid use at a dose of \>5 mg daily
• * Daily use of anti-inflammatory agents such as non-steroidal medications, or anticoagulants without medical supervision
• * Alcohol or drug addiction
• * Females who are pregnant, nursing, or planning pregnancy within the next year
• * Concomitant use of or unwillingness to avoid any use of weight loss medications, weight loss supplements, or weight loss herbal preparations
• * Has a condition or is in a situation which in the investigator's opinion may put the subject at significant risk or may interfere significantly with the subject's participation in the study